Comets are widely thought to be pristine remnants of the solar system's formation, and thus their study has been historically interpreted in that context. Evidence to date suggests that comets are far from pristine and the surfaces are heavily processed in very recent geological timescales.
Evidence presented here points to the overall shape of 67P Churyumov Geramisenko also being from a stretch event in very recent geological time scales rather than being from either directly from the surface processing or from its initial accretion from the solar system's formation.
This evidence falls into broad categories of: (NB. Click on the points for more detail and description of evidence for each point)
1) Matching large scale mirrored features from head to body around virtually the whole circumference of the nucleus.
2) Mini matches and 3D matches within high resolution images constrained by the position of the large scale matches.
3) Evidence of the removal of slabs due to the forces at play during stretch.
4) Cracks perpendicular to and crossing the rotation plane.
5) Monoliths matching their initial seating points.
6) Evidence of the head lobe stretching before breaking away.
7) Evidence of Dykes, slurry piles and related outgassing.
8) Evidence that would falsify Contact Binary and Erosion theories.
9) Sliding and Delaminating layers - Mainly sliding along the long axis through centrifugal forces, then delaminating radially outwards from the rotation axis.
Thus while still being extremely relevant to the understanding the history of the solar system, the extreme recent processing would mask any relevant evidence from the initial formation of the solar system, and asteroids are more likely to hold more clues in that direction, especially with impact crater records to verify age of surface.